FREIGHTLINER medium- and heavy-duty trucks will be equipped with more Mercedes-Benz engines and transmissions in 2004, the company says.

A new range of Mercedes-Benz diesel engines is available for Business Class medium trucks and heavy trucks. The MBE900 diesel is slated for the medium trucks. The engine is available in two configurations, a 4.3-liter four-cylinder version with horsepower ratings from 170 to 190, and a 7.2-liter version rated from 190 to 330 hp. Torque ratings for the MBE900 series range from 420 to 1,000 lb-ft. MBE900 engines have induction-hardened cylinder bores. The medium engines will be available in Freightliner Business Class trucks and Sterling Acterra trucks.

For heavy-duty applications, Freightliner offers the 12.8-liter MBE4000 with ratings from 350 to 450 hp and torque ratings from 1,350 to 1,450 lb-ft. The MBE4000 develops 90% of its available torque at 1,000 rpm, providing the capability to climb grades without excessive shifting. The MBE4000 is available in Freightliner Century S/T and Columbia tractors, and the heavy end of the Freightliner Business Class line, as well as in the Sterling A- and L-series trucks and tractor.

Both series of engines provide engine braking, with an exhaust brake, a compression brake, or a combination exhaust/compression brake on the MBE900 and an exhaust/compression brake on the MBE4000. The MBE900 can generate up to 215 braking horsepower, while the heavy-duty MBE4000 is good for up to 500 braking hp.

The engines use exhaust gas recirculation to meet EPA exhaust emission standards. Electronic fuel controls provide the capability to customize engine performance and to extract operating data for management and self-diagnosis for maintenance.

Warranties are three years or 150,000 miles for medium-duty engines in highway applications and two years with unlimited mileage for the heavy-duty MBE4000. Engine support is available from Freightliner, Sterling, and Detroit Diesel dealers. The engines will become available in the first quarter 2004.

Automatic with PTO

To make driving in congested traffic easier, Freightliner has introduced a Mercedes-Benz automated gear shift (AGS) transmission for Business Class trucks. The automated transmission will be available in the first quarter 2004.

The AGS transmission has a two-pedal, automated clutch actuation system with no manual shifting or clutch operation required. Removing the clutch pedal from the vehicle controls helps extend clutch and transmission life, and makes the transmission more economical to maintain. However, the AGS transmission can be shifted manually using the Freightliner SmartShift lever used to control other automated transmissions.

The AGS transmission is available with Mercedes-Benz MBE900 engines rated from 170 to 250 hp. Approved torque ratings are 520 lb-ft for vehicles weighing up to 40,000 lb and 660 lb-ft for 60,000 lb trucks. Both versions feature a right-side, high-output power take-off that is mounted in a 5 o'clock position to avoid exhaust system interference.

The transmission is controlled by an electronic transmission control unit that senses road and load conditions and grades to determine shift points for the most efficient operation and best fuel economy. The control unit selects the proper engine speed for a shift and engages smoother than a conventional manual transmission.

The AGS is based on a Mercedes-Benz six-speed transmission that has a long history of use in Europe. It has heat-treated steel alloy gears and sealed bearings in an aluminum alloy case with an integrated bell housing. The shift actuator is hydraulic.